There are many soft-tissue to bone repair procedures, such as rotator cuff, SLAP and Bankart lesion repairs, or reconstruction of labral tissue to the glenoid rim, in which a surgeon needs to secure tissue in close contact with bone by implanting an anchor, pre-loaded with suture, into a hole drilled in the bone at the desired anchor location. Commonly, the anchor which the sutures are attached to is made of either plastic such as PEEK or metal such as Titanium or Stainless Steel. In the case of an implant pulling out of the bone there is a piece of hard material from that implant floating inside the joint space. That piece of material could temporary or permanently be stuck within the joint, causing damage to the articulating surfaces.
Many surgeons are beginning to favor using all-suture suture anchors over traditional suture anchors. One particular advantage of using an all-suture anchor is that it requires a smaller hole to be drilled to the bone. Preserving bone is preferred by surgeons. There are quite a few all-suture anchor designs on the market today intended to capture this trend.
The JuggerKnot™, by Biomet, has its anchor configuration made of a section of #5-polyester suture. The loaded suture is inserted through the length of the #5 suture section of the anchor. The anchor is preloaded on an inserter at the middle point. The inserter pushes the anchor into a drilled hole in the bone until a desired position is reached. The inserter is then removed. Both suture limbs are lightly pulled to contract the anchor, expanding it laterally against the wall of the drilled hole. This design relies on the friction between the suture ball of the anchor and the bone. Depending upon the position inside the hole to which the anchor is deployed or set, anchor slippage may occur when higher tension applied on the anchor until the anchor may move to a harder bone surface such as the cortex.
ConMed Linvatec also has introduced an anchor called the Y-Knot™. The anchor is very much the same construct as the Biomet JuggerKnot anchor in terms of design, but with different suture material. It uses high-strength suture for the anchor instead of polyester suture. The technique for using the anchor is also very similar as the company suggests in its own words: “Drill Pilot Hole, Insert Anchor, and Pull-to set.” Since the anchor designs and techniques are similar, the anchor shares the same weakness of relying on friction. Thus, slippage can occur, and pull out strength could not be adequate.
Another similar anchor is from Stryker and is called Iconix™. The anchor is designed to have opening sections along the sheet portion, which claim to provide a bunching effect using targeted compression zones. The middle point of the anchor is also preloaded on an inserter and inserted into a pre-drilled hole. When deployed by applying tension on the pre-loaded suture limbs, instead of the whole section of the anchor expanding randomly within the hole, those opening sections on the anchor are intended to swing outward laterally up to 3 mm-4 mm. However, such claimed expansion dimensions are theoretical only, because the soft suture is not stiff enough to penetrate the hole to achieve such dimensions in practice.